The present invention relates to a CR-type oscillator circuit and, more particularly, to a CR-type oscillator circuit having a high stability with respect to oscillation frequency.
As a conventional typical CR-type oscillator circuit, there has been known a circuit which includes a reference resistor, a current mirror circuit and a reference capacitor and in which the current flowing in the reference resistor is taken out by the current mirror circuit for repeating the charging and discharging of the reference capacitor. However, in such a circuit, the ratio between the potential changing range in the repeated charging and discharging of the reference capacitor and the potential differences appearing across the reference resistor was not maintained constant because of, for example, the changes in power supply voltages, so that it was difficult to avoid variations in oscillation frequency.